This Warning event indicates that the specified number of users have greatly exceeded the specified threshold for the specified component. This event is logged for all users who exceed the limit, regardless of how far over the limit an individual user has gone. A separate event message, event 2915, is logged for each user who greatly exceeds the limit.

This error can be safely ignored if you see it logged infrequently. This is because it can correspond to momentary Active Directory access or RPC latencies. However, if you see this error with some regularity, look for corresponding 2915 events in the event log. For detailed troubleshooting steps, see MSExchange ADAccess 2915.